@inproceedings{maddison2016concrete,
  title={The concrete distribution: A continuous relaxation of discrete random variables},
  author={Maddison, Chris J and Mnih, Andriy and Teh, Yee Whye},
  booktitle={International Conference on Learning Representations},
  year={2017},
  url={http://www.stats.ox.ac.uk/~cmaddis/pubs/concrete.pdf}
}